The modding scene for RE3 demo ended up becoming super active! Here’s a collection of mod showcases of mods made by myself and other modders:
If anyone wants to mod the demo, you can download my mod manager with RE3 demo support from here: https://www.fluffyquack.com/news/mod-manager-with-resident-evil-3-demo-support/
Some mods are downloadable from the mod manager itself, and it also includes links to sites with more RE3 demo mods.